Global statistics

Demography

Total number of rats	50,447 rats
⨽ females	⨽ 25,865 females (51.27 %)
⨽ males	⨽ 24,582 males (48.73 %)

Rats considered as deceased	47,575 rats (94.3 % of all rats)
⨽ declared with known date	⨽ 22,814 rats (48 % of deceased rats)
⨽ presumably dead	⨽ 24,761 rats (52 % of deceased rats)

Lifespan
⨽ average	⨽ 22.2 months (♀: 22.7 months – ♂: 21.8 months)
⨽ average, infant mortality excluded	⨽ 22.7 months (♀: 23.1 months – ♂: 22.3 months)
⨽ average, accidents also excluded	⨽ 23.5 months (♀: 23.8 months – ♂: 23.1 months)
⨽ maximum	⨽ 4 years, 3 months, 28 days (DS. Cerberus)

Breeding

Total number of ratteries	692 ratteries
⨽ active in the last 2 years	⨽ 33 ratteries (4.77 %)

Average rattery lifetime	921 days (2.5 years)
Average rattery productivity	8.5 litters (45.7 rats)
⨽ as birth place	⨽ 6.8 internal litters
⨽ as other contributor	⨽ 1.8 external litters

Average mother age	233 days (7.6 months)
Average father age	441 days (14.4 months)
Average litter size	6.6 pups (debiased estimation: 10.3 pups)
Average sex ratio	0.986 (about 101 females for 100 males)

Mortality

Median death age	23 months (50 % of rats die before this age, 50 % after)
Death peak	24 months (death occurs more often at this age than any other)
Interquartile interval	16-27 months (50 % of rats die in this age interval)
Leading death category	“Other” (24 % of declared deaths)
Leading death cause	“*Old age, natural death (from 24 month old minimum)” (22 % of declared deaths)

Death categories

Number of recorded deaths	22,814 rats (48 % of rats considered as dead)
By decreasing frequency	* please note that tumours without recorded localization appear as « Autres »

24.02 %	Other
22.5 %	Old age, natural death (from 24 month old minimum)
16.88 %	Unknown cause
12.87 %	Respiratory
7.77 %	Accidents, traumas, poisonings
7.2 %	Neurological (brain, spinal cords, nerves)
2.22 %	Infant mortality (up to 6 week old)
1.63 %	Eye, ear, mouth, face
1.6 %	Reproductive system
1.23 %	Cardiovascular
1.04 %	Digestive
0.75 %	Urinary system (kidney, bladder)
0.25 %	Skin
0.08 %	Muscles and skeleton

Most frequent death causes

Number of deaths with recorded cause	22,814 rats (48 % of rats considered as dead)
By decreasing frequency	* for rats recorded as dead without precise cause, death category is used instead

22.5 %	*Old age, natural death (from 24 month old minimum)
16.84 %	Undetermined cause (known date)
13.87 %	Undetermined tumor (affected organ unknown)
7.42 %	*Respiratory
4.78 %	Bronchitis, pneumonia
4.58 %	Domestic accident (crush, door...)
4.41 %	Undetermined infection or abscess
4.09 %	Stroke
3.04 %	*Other
2.13 %	Virus, epidemic outbreak, immune deficiency (SDA, Sendai, Tyzzer...)
1.9 %	*Neurological (brain, spinal cords, nerves)
1.49 %	Veterinary accident (anesthesia during a minor operation, medical error, etc.)
1.14 %	Fights, injuries, serious bites, subsequent hemorrhage (excluding abnormal hemorrhage)
1.06 %	*Infant mortality (up to 6 week old)
0.94 %	Heart failure, valvular disease
0.77 %	Stillborn
0.75 %	Pituitary tumor
0.69 %	Mammary tumor
0.58 %	Otitis, ear abscess
0.46 %	Complications of gestation or parturition
0.44 %	Renal failure
0.33 %	Lung tumor
0.31 %	Facial tumor (excluding Zymbal tumor)
0.3 %	Zymbal gland tumor
0.27 %	Digestive tumor (stomach, liver, pancreas, intestines...)
0.27 %	Intestinal obstruction (excluding megacolon)
0.21 %	Lack of milk
0.21 %	Generalized cancer, leukemia, lymphoma
0.2 %	Epilepsy
0.2 %	Pulmonary edema
0.18 %	Uterus infection (metritis, pyometra)
0.17 %	Food poisoning
0.17 %	Hereditary megacolon
0.15 %	Other respiratory trouble
0.15 %	Brain tumor
0.14 %	Liver failure
0.13 %	Tooth abscess
0.13 %	Heart attack, infarct, pulmonary embolism
0.13 %	Heatstroke
0.12 %	Other tumor (salivary, spleen, adrenal, thyroid...)
0.12 %	Uterine tumor
0.11 %	Falls, fractures, head or spinal cord trauma (excluding fights)
0.11 %	Malformation, hydrocephalus
0.11 %	*Urinary system (kidney, bladder)
0.1 %	Facial abscess (excluding teeth and Zymbal gland)
0.1 %	Suffocation, choking
0.1 %	Other heart or vascular problem
0.09 %	Dental malocclusion
0.08 %	*Skin
0.08 %	Sepsis
0.08 %	Pododermatitis
0.07 %	Kidney tumor
0.07 %	Other digestive trouble
0.07 %	Other infant mortality cause
0.06 %	Vaginal prolapse (excluding tumors and postpartum)
0.05 %	Other neurological trouble
0.05 %	Hemorrhage (exaggerated relative to the context, coagulation disorder, hemophilia)
0.05 %	*Unknown cause
0.04 %	Urinary or kidney infection
0.04 %	Other known cause fitting no other category
0.04 %	Digestive abscess
0.04 %	Other head or neck related trouble
0.04 %	*Eye, ear, mouth, face
0.04 %	Allergy, anaphylactic shock
0.04 %	Other urinary disorder
0.04 %	Progressive spinal cord damage, degenerative paralysis
0.04 %	Diabetes
0.04 %	Subcutaneous abscess
0.04 %	Skin tumor, skin cancer
0.04 %	Digestive hemorrhage
0.04 %	Other reproductive system disorder
0.04 %	Bladder tumor
0.03 %	Bone tumor
0.03 %	Muscle tumor
0.03 %	Brain infection, encephalitis, meningitis
0.03 %	Euthanasia without medical cause
0.02 %	Retro-orbital abscess
0.02 %	Other accident or trauma
0.02 %	Malnutrition
0.02 %	*Accidents, traumas, poisonings
0.02 %	Ovarian tumor
0.02 %	Urethral obstruction, urinary retention, stones
0.02 %	*Cardiovascular
0.02 %	*Digestive
0.01 %	Vaginal tumor
0.01 %	Other musculoskeletal trouble
0.01 %	Testicular tumor
0.01 %	Extensive skin infection (pyoderma, bedsores, etc.)
0.01 %	*Reproductive system
0.01 %	Gastroenteritis, diarrhea
0.01 %	Joint or bone infection, septic arthritis
0.01 %	Poisoning (household products, poisons, stolen medicines, etc.)
0.01 %	Glaucoma
0.01 %	Retro-orbital tumor
0 %	Preputial gland tumor
0 %	Parasites

Most frequent tumours

Number of tumour-related deaths	3,964 rats (17.38 % of rats with known death cause)
By decreasing frequency	* please note that tumour localization could not be recorded before 2023

79.84 %	Undetermined tumor (affected organ unknown)
4.29 %	Pituitary tumor
3.99 %	Mammary tumor
1.89 %	Lung tumor
1.77 %	Facial tumor (excluding Zymbal tumor)
1.72 %	Zymbal gland tumor
1.56 %	Digestive tumor (stomach, liver, pancreas, intestines...)
1.24 %	Generalized cancer, leukemia, lymphoma
0.86 %	Brain tumor
0.68 %	Uterine tumor
0.68 %	Other tumor (salivary, spleen, adrenal, thyroid...)
0.43 %	Kidney tumor
0.2 %	Skin tumor, skin cancer
0.2 %	Bladder tumor
0.18 %	Bone tumor
0.15 %	Muscle tumor
0.1 %	Ovarian tumor
0.08 %	Vaginal tumor
0.08 %	Testicular tumor
0.05 %	Retro-orbital tumor
0.03 %	Preputial gland tumor